1. Field of the Invention
The present invention relates to a can lid feeder that is applicable for use with a can seamer for making aluminum cans, iron cans or the like to be filled with beer, coffee, juice, etc.
2. Description of the Prior Art
A separator/feeder for can lids has been heretofore proposed, for instance, in Laid-Open Japanese Patent Specification No. 56-139242 (1981). In this separator/feeder shown in FIG. 11, a separator 1 is rotatably driven by a rotary shaft 8 that is in turn driven via a gear train 6 off of a drive shaft 5 of a can drum turret 4. Can lids 7 drop through a drop hole at the bottom of a hopper and are stacked in an inclined state with one edge of the stack placed on the top of a screw groove 9 of the separator 1. As the separator 1 rotates, one can lid at the bottom of the stack is lowered as guided by the screw groove 9 of the separator 1 to be fed whereby the next step of a process is carried out.
In addition, various kinds of can lid feeders for use with a can seamer have been heretofore proposed. In one example of such proposed can lid feeders shown in FIG. 13, cans 102 filled with liquid in a filler 101 are fed into a seaming turret 104 as conveyed by a can feed conveyor 103. Reference numeral 105 designates a can lid feeding turret disposed contiguously to the seaming turret 104. On the outer circumference thereof are formed guide grooves 105a similar to the guide grooves 104a for the cans 102 provided on the outer circumference of the seaming turret 104. Can lids 107 are made to fall onto the guide grooves 105a from a can lid feeding mechanism 106 disposed above turret 105, and a lid 107 which has been made to fall is fed onto a can 102 which has been conveyed by the can feed conveyor 103 and is about to be fed to the seaming turret 104. Thereafter, the can 102 and the lid 107 sent into the seaming turret 104 are subjected to a seaming operation by means of seaming rolls disposed around the seaming turret 104 (not shown). Thus, a completed packaging can 102' is sent through an outlet turret 108 whereby the next step of the process is carried out.
In the heretofore known can lid separator/feeder shown in FIG. 11, the separator 1 was fixed in position so as to be rotated about the axis of the rotary shaft 8. Accordingly, if the diameter of the can lid 7 was changed, it was necessary to always match the outer diameter of the separator 1 with the outer circumference of the can lid 7, and hence the separator had to be replaced by another separator matched with the new can lid. However, since the above-mentioned separator 1 could not be moved in the radial direction, the entire drive mechanism, that is, a gear train 6, a rotary shaft 8 and the like mounted with a separator matched with the changed can lid diameter had to be replaced. Therefore, there were shortcomings in that not only did numerous ones of the aforementioned drive mechanisms have to be prepared but also the exchanging thereof necessitated a long time.
In addition, the separator 1 in the above-described heretofore known can lid separator/feeder was provided with only one screw groove 9 as shown in FIG. 12. Accordingly, in the even that cans were conveyed at a high speed by a can feed conveyor traveling at a high speed, in accordance with the can feeding speed it was necessary to also feed the can lids at a high speed. As the separator 1 could separate and feed only one can lid during its one revolution, it was necessary to also rotate the separator 1 at a high rotational speed in accordance with the speed of the conveyor along which the cans filled with liquid were traveling. During this process, since the can lid was moved downwards with its one end engaged with the screw groove 9 as shown in FIG. 11, in the event that the separator 1 was rotated at a high speed, the extent of abrasion of the can lid was large and the side of the separator was also furiously abraded.
Further, in the apparatus shown in FIG. 11, since the cans 102 filled with liquid by the filler 1 and being conveyed by the can feed conveyor 103 did not yet have can lids placed thereon and, moreover, since the cans 102 were being conveyed at a considerably high speed, liquid would spill from the cans on the can feed conveyor 103, especially at the inlet of the seaming turret 104 where the can lid 107 was about to be fed, due to the fact that the can 102 began to rotate as a result of the transfer thereof onto a lifter (not shown) under a condition in which the can lid 107 had not yet been perfectly put on the can 102.